Howard Stern, who starts as a judge on “America’s Got Talent” next week, says it was his father who prepared him for the job.

“He never pulled any punches with me. He was blunt,” the controversial radio host told The Post.

He specialized in the bucket-of-cold-water school of advice, Stern says — and it’s what he plans to do, too.

“When I was a disc jockey in college, I sent him a tape of mine, and he wrote me back a letter. It was harsh. He said, ‘You sound horrible! Every other word is ‘uh, uh, uh.’ You are verbose. You are not getting to the point,’ ” he says, “ And that really spoke to me.

“My daughter said to me, ‘Dad, are you going to be awfully mean to people?’ ” he says. “And I said, ‘No. I am going to be honest.’ ”

Stern says he has some small-scale experience with the pull-no-punches approaches while raising his own three girls.

When daughter Emily, now 28, performed in school plays, “I would go to her and say, ‘Here is what I loved, and here is what I thought. I would be very specific,” he remembers. “And I would be very encouraging.

“But to walk up to somebody who wants to be in show business and say, ‘You were the best!’ What does that mean? If you are dishonest, you are not doing that contestant a favor.”

Stern — who will reportedly earn $20 million to critique jugglers, singers and water-skiing squirrels — admits he has, on occasion, come right out and told some auditioners, “You are no good.”

One of the worst acts, he says, performed musical instruments crafted out of suitcases.

“I said, ‘You should take those suitcases and pack your bags and go home. At least you could put them to use,” Stern remembers.

“I was being harsh. But at the same time, they needed to know they were awful. And they shouldn’t waste their time in show business.”

The crowds in most audition cities were noticeably pro-Stern, according to early reports.

But the foul-mouthed, stripper-loving King of All Media is not what you’ll see on “AGT,” Stern says.

“People have all of these preconceived ideas,” Stern insists. “They feel safe with Howie [Mandel] and Sharon [Osbourne], because they know them. I don’t want to be the guy that comes in and ruins it . . . I am not the devil. I am not a monster.”

Still, Stern admits had some moments he wishes he could take back.

He “melted” inside, he confessed, after reducing a second-grader to tears during the New York tryouts last month — while Stern’s own father watched from the audience.

“I ran up on the stage and started hugging [the second grader],” he says. “I couldn’t handle it.

“But this is the job I was given. I am not going to sit there and suck up to a 7-year-old.”

Speculation over Stern’s next move in show business will probably begin again soon after he starts on the TV series, his first since his own, risque late-night show of the 1990s.

Stern is appealing a $300 million legal dispute with SiriusXM satellite radio, which carries his daily morning show.

Last month he threatened to leave the company and return to terrestrial radio if the dispute is not settled.

In the meantime, NBC has made Stern the face of their highest-rated summer show — and relocated the production to New Jersey to accommodate his schedule — without a firm commitment he will return again next season.

“Let’s see what America has to say first,” Stern says. “I don’t know that they will like me as a judge — but I hope they do.”